Can lie detector be used as evidence in a murder case?

Question

i've always wondered why they go through all those time and money to gather evidence when they can simply give the suspect a lie detector test since its like 99.9% accurate and prosecute them base on that or is that invalid in the court of law?

Answer 1

you're accuracy of lie detectors is WAY OFF which is why they are not permitted as evidence in court

Answer 2

i agree with above post lie dector is not 99.9 % but is used in connection with other procedures to determine but can not be used a sole evidence like DNA
aslo as stated above inorder for scientfic evidence to be entered it must either past a doubert or frye test and in this case if one side objects and asked for a frye test it may or may not meet the requirments

us supreme court case where a solider test positive for drugs but took a lie dector test to prove he had no knoweldge he passed but us said the lie dector could not over rule the blood evidence which showed he had drugs

it is also possible to beat the test, first controll questions are asked if the response to those questions can be effected then the rest of test is flawed

Answer 3

A: Federal courts have ruled that polygraph is NOT per-se inadmissible in a court procedure, but that it may be considered when standard rules of scientific evidence have been met. In other words, applicants must apply to the judge for admissibility under the "Daubert" standard of evidence on a case-by-case basis. Individual judges can still decline to accept polygraph results, however. Each jurisdiction must be checked to determine admissibility standards. One of the greatest fears keeping polygraph evidence out of courts is the fact that such evidence would carry greater weight than other equally-important evidence and would tend to sway a jury in one direction even though other evidence may point the other way. In most cases, polygraph evidence is used during pre-trial negotiations and plea bargain agreements rather than during the trial itself. For more information : Admissibility of Polygraph


Admissibility - Polygraph results (or psychophysiological detection of deception examinations) are admissible in some federal circuits and some states. More often, such evidence is admissible where the parties have agreed to their admissibility before the examination is given, under terms of a stipulation. Some jurisdictions have absolute bans on admissibility of polygraph results as evidence and even the suggestion that a polygraph examination is involved is sufficient to cause a retrial. The United States Supreme Court has yet to rule on the issue of admissibility, so the rules in federal circuits vary considerably. The Supreme Court has said, in passing, that polygraph examinations raise the issue of Fifth Amendment protection, [Schmerber v. California, 86 S. Ct. 1826 (l966).] The Supreme Court has also held that a Miranda warning before a polygraph examination is sufficient to allow admissibility of a confession that follows an examination, [Wyrick v. Fields, 103 S. Ct. 394 (1982).] In 1993, the Supreme Court removed the restrictive requirements of the 1923 Frye decision on scientific evidence and said Rule 702 requirements were sufficient, [Daubert v. Mettell Dow Pharmaceutcals, 113 S.ct. 2786.]Daubert did not involve lie detection, per se, as an issue, as Frye did, but it had a profound effect on admissibility of polygraph results as evidence, when proffered by the defendants under the principles embodied in the Federal Rules of Evidence expressed in Daubert, see [United States v. Posado (5th Cir. 1995) WL 368417.] Some circuits already have specific rules for admissibility, such as the 11th Circuit which specifies what must be done for polygraph results to be admitted over objection, or under stipulation, [United States v. Piccinonna 885 F.2d 1529 (11th Cir. 1989).] Other circuits have left the decision to the discretion of the trial judge. The rules that states and federal circuits generally follow in stipulated admissibility were established in [State v. Valdez, 371 P.2d 894 (Arizona, 1962).] The rules followed when polygraph results are admitted over objection of opposing counsel usually cite [State v. Dorsey, 539 P.2d 204 (New Mexico, 1975).] Primarily because of Daubert, as well as the impact the other cited cases have had, polygraph examination admissibility is changing in many states. Many appeals, based on the exclusion of polygraph evidence at trial are now under review by appellate courts.

Answer 4

No b-cuz lie detector tests are inadmissable in courts of law, they can jsut reveal the findings, but can help in no way to convict or exhonerate one under suspicion

Answer 5

yeah i think its against law because its not 100%. it can be supportive evidence but not the only evidence to show someone as murderer. you have to link them to crime scene.

Answer 6

It can be,but I think they are starting to rely on them less and less,because of how theyve been shown to beeasy to pass.